Robot Standard Improves Safety, Permits Collaboration

Updated ANSI/RIA R15.06 aids in regulatory compliance and helps create a new class of robots

The role of standards is often to help create the infrastructure for innovative technological advances. The latest update of a robotics safety standard does that, but it also helps set the stage for the emerging field of collaborative robots.

The Robotic Industries Association has updated ANSI/RIA R15.06 which was last revised in 1999. It was the basis of ISO 10218, which came out in 2011. RIA’s update makes a wide range of alterations, including risk assessment, fixed guard dimensions, safety control circuitry requirements and terminology. Collaborative robots also make it easier for humans to work closely with robots.

The high points of the new document are detailed in a webcast, Understanding the Changes in the Industrial Robotic Safety Standard.

“There are six reasons to be excited about the new standard,” says Pat Davison, director of standards development at the Robotic Industries Association.

The new area of collaborative robots is getting the most attention. ANSI/RIA R15.06 helps make it easier for robots and humans to work closely in the same work cell.

“Collaborative terminology helps in the development of robots designed for direct interactions with humans in a defined workspace,” Davison says. “Humans and robots perform tasks simultaneously.”

Most of the requirements can only be met by robots designed specifically for collaboration, he explains. Among these is a restriction that when humans are in a situation where the robot could injure them or damage something, robots must have a monitored stop function in which they remain powered up and ready to resume operating normally. Collaborative robots must also permit hand-guided operation for continuous work rather than the existing hand-guided modes that are only for teaching.

Most of the other reasons for excitement address more mainstream aspects of industrial robotics, Davison says. One is that ANSI/RIA R15.06 now complies with U.S. safety requirements set by the Occupational Safety and Health Administration. OSHA’s general duty clause requires that places of employment are free from recognized hazards.

The standard addresses three groups: equipment manufacturers, integrators and users. In contrast, ISO documents omit users because with international standards, it’s quite difficult to pre-determine the operating environments in all regions.

Although ANSI documents don’t have the weight of law, ANSI/RIA R15.06 provides guidance that help plant managers ensure that user environments meet OSHA requirements written to safeguard humans and equipment. Buying robots and end effectors that comply with safety standards like ANSI/RIA R15.06 is an important starting point in creating safe working environments. The document also discusses ways that risk assessment concepts can be used to improve protective strategies.

The changes also optimize floor space, reducing the amount of clearance required around robot cells. The 1999 version required up to 18 inches of clearance between potential hazard areas and safeguards. Now, that 18-inch requirement isn’t needed if operators won’t be in an area. For example, a robot can be situated close to walls in a corner because people won’t between the wall and the machine.

The updated document also quantifies safety ratings, making it easier to determine whether safety requirements are being met. For example, meeting SIL3 obligations means ensuring that no single fault causes the loss of safety functions and detecting all faults before the next demand for a safety function. The changes also make it easier to determine compliance with related standards such as ISO 13849 and IEC 62061.

As with most revisions of standards, the update changes some definitions while also adapting to the changing demands caused by globalization. Users in many different countries will be able to read versions written in their native language, reducing the likelihood of errors that sometimes arise when non-native speakers misunderstand some verbiage in English versions of standards.

“This is an international standard that’s being printed in multiple languages,” Davison says. “It also has new terminology.”

For example, the definition of a robot does not include any end effectors, while a robot system is now defined as the robot and its end effectors. A robotic cell includes both a robot system and its safeguarding equipment. Slow speed addresses movement of less than 250 mm per second, while teach mode describes manual operation at reduced speeds used to program the robot. The term operator means any human, including visitors.

The latest upgrade is another step in an ongoing race to improve the safety of workers and equipment in facilities that utilize robots. The first version of ANSI/RIA R15.06 came out in 1986, roughly 20 years after the first robots were used in industrial standard environments. Thirteen years passed before it was updated in 1999. In 2006, ISO completed its 10218 document, which was updated in 2011. The next year, ANSI adopted ISO 10218.

The updated standard now provides global harmonization, ensuring that robots that are compliant can be used nearly anywhere around the globe. The only caveat is that Canada’s CSA Z434 standard has some differences that require a bit of attention.

This harmonization, along with the other changes in the update, should continue to help the robotic industry expand its role in industrial automation. As the roles and usage of robots grow, ANSI/RIA R15.06 will also help protect workers and let industrial sites improve their efficiency while enhancing the protective steps that keep workplace environments safe.